Display package and method of producing same



Dec. 16, 1958 R. K. FIOTTLE l-:T AL

DISPLAY PACKAGE AND METHOD OF PRODUCING SAME 2 Sheets-Sheet l FiledApril 21, 1955 Cv i mw@ (fw mx W F A @D V.. B

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R. K. PoTTLE ET AL 2,864,710

DISPLAY PACKAGE AND METHOD OF PRODUCING SAME Filed April 21, 1955 Dec.16, 195s 2 Sheets-Sheet 2 @gf JNVENTOR5. @u p/,f K. P07725 nited StatesPatent DISPLAY PACKAGE AND METHD F PRODUCENG SAME Ralph K. Pottle,Georgetown, Conn., and Oscar F. Ecklund, Barrington, Ill., assignors toAmerican Can Company, New York, N. Y., a corporation of New JerseyApplication April 21, 1955, Serial No. 502,766

4 Claims. (Cl. 99-171) The present invention relates to packaging foodproducts and the like and has particular reference to a food or otherproduct containing display package having a thin, ilexible, frangible,gasproof and transparent plastic wrapper hermetically joined to a rigidsupport member and to a method of producing the same.

Thin frangible plastic materials alone have been used to some extent topackage food products and occasionally such packages have beeninteriorly vacuumized to preserve the product. However, considerabletrouble has been experienced in holding a vacuum in such a package dueto flexing and deformation of the package under normal commercialhandling. To overcome this diculty rigid members have been used tosupport the product. This however is only a partial remedy since therigid member itself must be made leakproof and the plastic material mustbe hermetically and strongly attached to the member. This latterrequirement of sealing the plastic material to the rigid membereectively has proved to be a diflicult problem, especially where therigid member is made of sheet metal and metal flanges are used to crimpthe plastic material tautly in place, for the sharp edges of metalflanges have a tendency to cut the plastic material in the formation ofclosure joints. Attempts have heretofore been made to cushion thecontact between metal and plastic material with the help of libre ringsor collars or gaskets. This adds considerably to the cost of the packageand its assembly.

An object of the instant invention therefore is to provide a productcontaining display package having a thin, flexible, frangible andtransparent plastic wrapper covering the product and hermetically sealedto a rigid hermetic support member so as to provide economicalprotection and support for the product and at the same time provide formaximum visibility of the product.

Another object is the provision of such a package and a method ofproducing it wherein a sheet metal can end is utilized to support theproduct and wherein the plastic material is locked or interfolded with aange on the can end in an economical and simple manner to provide asecure tight seal for the protection of the plastic material and theproduct covered thereby.

Another object is the provision of a metallic can end seam for such apackage and a method of producing the same wherein the plastic materialalone Without the use of additional cushioning members is effectivelysealed in the seam.

Another object is the provision of such a package and a method ofproducing it wherein a thin, flexible, frangible, transparent andgasproof plastic wrapper and the rigid hermetic support member arebrought together in a manner which permits of vacuumizing the interiorof the package prior to sealing to produce a vacuumized unitarystructure.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, takenin connection with ice Figs. 3 and 4 are greatly enlargedfragmentarysectional views of the end seam of the package as takensubstantially along planes indicated by the lines 3-3 vand 4-4 in Fig.1;

Fig. 5 lis an enlarged schematic view of one of the folds at the endseam in the wrapper of the package;

Fig. 6 is a sectional plan view through the end seam at one of thefolds, as taken substantially along the line 6-6 in Fig. 4; and

Figs. 7 to 13 inclusive are schematic sectional views showing thevarious steps of producing the package illustrated in Fig. 1, inaccordance with the method portion of the invention, Fig. 13 being asectional view taken substantially along the line 13-13 in Fig. 9.

As a preferred or exemplary embodiment of the instant invention Figs. 1to 6 inclusive of the drawings illustrate a display package for foodproducts and the like, comprising a rigid base or support member 21(Figs. 1 and 2) for holding a product A and a thin, flexible, frangible,gasproof and transparent wrapper or cover 22 secured to the rigidsupport 21 in a suitable joint or seam 23 for protecting the product.The interior of the package may or may not be vacuumized, as desired.

The rigid base or support member 21 is slightly larger dimensionallythan the overall dimensions of the product in order to insure full`support for the product and to provide marginal portions foriuterengagement with a closure or wrapper. This member 21 preferably ismade of sheet metal, such as tin plate or the like although othermaterials may be utilized if desired. The member 21 preferably is shapedin the form of a can end, many sizes of which are readily available,together with equipment for making'them. It comprises a raised panel 25(Fig. 2) on which the product rests and which is surrounded by adepending skirt wall 26 terminating at its lower edge in an outwardlyprojecting annular flange 27 incorporated in the joint or seam 23 andcarrying a compound lining or gasket 28 (Figs. 3 and 4). The entiremember 21 or any portion thereof may carry one or more protectivecoatings, such as lacquer, enamel or other substances.

The thin, flexible, fraugible, gasproof and transparent wrapper or coveror closure 22 preferably is made of a plastic film material such asSaran (a vinylidene chloride polymer) and Mylar (an oriented linearpolyester resin). However other thin, flexible, frangible audtransparent film materials such as cellophane, Pliotilm and the like maybe used if desired. The lm of plastic material preferably is of doubleply, approximately .0015 inch thick, to produce greater llexibility andresistance to abuse and soft enough to be substantially self-sealingwhen folded.

The wrapper or cover 22 lies over the top of the product on the supportmember 21 and extends down along the sides rof the product andistinterfolded in the seam 23 with the flange 27 of the support member21, thereby with the support member entirely enclosing the product. Inthe seam 23 the wrapper 22 is embedded in the compound gasket 28 andfollows the shape of the seam along the inner compound lined surfacethereof (see Figs. 3 and 4), forming a loop within the seam, bendingback on itself at a point 31 of sealing and terminating just outside ofthe seam adjacent the skirt wall 26 of the support member 21.

The seam 23 preferablyis produced by curling the support member flange27 upwardly and inwardly against the skirt wall 26 of the member in sucha manner as to tightly lock the bent-backuponitself marginal edgeportion of the wrapper in the seam without cutting or otherwise iniuringthe wrapper. For this purpose the seam include s a smooth convexlycurved annular wall section 32 having a relatively large cross-sectionalradius (Figs. 3 and 4), which wall is disposed in tangential relation tothe outer face of the support skirt wall 26. with the wrapper 22interposed between the skirt^wall and the curved wall section and withthe curved wallV section tightly pressing the Wrapper against thecompound 28 on the skirt wall thus providing a cushioned hermetic Joint.

The curved wall section 32 is maintained in this wranper sealing andlocking position preferably by an inwardly proiectmg annular bead 34which is formed in the outer vertical wall of the seam and which extendsentirely around the seam. This bead 34 preferably is disposed at aposition substantially one third of the height of the seam from thelower edge thereof. The inwardly pro- ]ecting annular bead 34 in thisposition sets off a relatively sharp radius bend or outwardly nroiectingannular bead 35 at the bottom of the seam. The bend or bead 35 is ofsmaller radius than the portion of the seam above the inwardlyproiecting bead 34 and thus is stiffer (i. e. less flexible) and hencemaintains suicient pressure on the curved wall section 32 to keep thelatter clamped against the bent-back-upon-itself wrapper 22 to lock thewrapper in place.

When the package is of cylindrical or circular formation. the coveringof the product with the film of plastic material results in a series ofperipheral folds or pleats 37 (Figs. l, 2, 4 and 5)l which are spaced atintervals around the vertical sides of the product. These folds createirregularities in the seam since at places between the folds only twothicknesses of the film are incorporated in the seam as shown in Figs.3, 5 and 6 and in places where the folds occur six thicknesses arepresent as shown in Figs. 4 and 6. However the compound 28 in the seam,serving as a sealant and a cushion, is forced into the interstices ofthe folds and adjacent the edges of the folds and thus seals theseinterstices hermetically.

Thus, through the medium of the particular form of ioint or seam 23. themarginal edge portions Aof the, plastic film or wrapper 22 alone,without the aid of Supplemental members such as ring or c ollar membersand the like, are tightly and hermetically locked in the seam, therebypermanently uniting the wrapper 22 and the product support member 21 asa unit display package., Removal of the product from the package iseffectedthrough tearing away the wrapper 22. IThe product A may be onevof many kinds. Sliced meat or cheese are only two of many examples.

In the method of producing such a display package, as illustrated inFigs. 7 to l2 inclusive, the product A, for example a stack ofpressedmeat, is first placed on a rigid support member 21 having a skirt wall26 and a protecting ange 27 carrying a compound gasket 28 as shown inFig. 7.

As the second step in the method, the top and sides of the product A arecovered loosely by and thus enclosed in a thin, flexible, frangible,gasprooi and transparent wrapper 22, preferably a plastic film materialwrapper (seeFig. 8). This step may beelectedin any suitable manner asyby` laying a film of a precutpiece of wrapper material over the top oftheproduct and .pressing it down around the sides of the productorbypreforming the film into a cup shape and placing the cup over theproduct or by a combination of these procedures. The wrapper may beanintegral portion of asubstantially continuous web 4 or strip or may be asevered portion, such as a predetermined size blank, if desired.

When the interior of the package is to be vacuumized, the wrapper 22should fit loosely over the product so as to provide ample space aroundthe product for adequate movement of the wrapper inwardly against theproduct without tension when a vacuum is drawn during the seamingoperation.

With the wrapper 22 in place over the product A, the portions extendingdown along the sides of the product are tucked or seated into thecompound gasket 28 in the ange 27 of the rigid support member 21 toimbed it in the compound as shown in Fig. 9.` The imbedding of thewrapper into the compound preferably is effected at spaced intervalsonly, as shown in Fig. 13, around the flange so as to leave untucked orunimbedded portions between the imbedded portions to provide vents orchannels 39 through which the interior of the package is subsequentlyvacuumized by drawing the air through the vents.

The excess surrounding portion of the tucked-in wrapper, i. e, thatportion which extends beyond the flange 27 of the support member 21, isthen trimmed or sheared off as shown in Fig. 10. This trimming step maybe omitted if the wrapper is precut as a predetermined size blank to fitthe package.

Following the tucking and trimming steps, the partially formed packageis introduced into a vacuum chamber 41 (Fig. 1l). In this chamber, avacuum of from 25 to 29 inches of mercury (depending upon the degree ofultimate vacuumization desired) is drawn on the package to exhaust theair from its interior through the vents 39 formed by the untuckedportions of the wrapper 22 (Fig. 13). While in this chamber and whileheld under vacu um, the marginal edge portion of the wrapper is fullyseated in place entirely around the flange 27 to close and seal thevents and to imbed the wrapper in the compound 28 in a continuousannular seal. This is effected by a tubular shape seating tool 42 (Fig.1l).

As soon as this complete seating step is accomplished, the flange 27 isbent inwardly against the support member skirt wallI 26 to produce theseam 23. This bending of the flange 27 preferably is effected by aconventional seaming head having first and second operation seamingrollers 43, 44 (Fig. 12) located within the chamber 41. The firstoperation roller 43 forms the curved wall section 32 of the seam 23 andbends this wall section inwardly against the wrapper 22 and skirt wall26 of the support member 21. The second operation roller 44 finishesthis bending operation and forms the inwardly extending bead 34 in theseam and the sharp radius curved wall section or outwardly extendingannular bead 35 which clamps the wall section 32 against the skirt walll26. This seaming opera tion hermetically seals the bent back upon itselfmarginal edge portion of the wrapper 22 alone, without the aid of asupplemental member, into the seam to permanently unite the wrapper andthe rigid support member 21 into a unitary structure. This bending ofthe flange 27 is effected while the package is maintained under vacuumin the chamber 41 as shown in Fig. l2.

Upon breaking the vacuum in the chamber 41 to remove the package toatmospheric conditions, the pressure of the Outside air against thewrapper 22 forces it inwardly toward the product on the rigid supportmember 21 and thus causes the wrapper to cling to the product andthereby bond or tie together the wrapper, the product and the supportmember as a firm unitary package which may be readily handledcommercially without fear of failure.

In some cases the interior of the package may be protected by displacingthe air therein with an inert gas, such as carbon dioxide or nitrogen,instead of yacuumization. This may be effected in the chamber 41, eitherwith or without prevacuumizing and prior to the forming of the seam 23as hereinbefore described.

If the interiot of the package is to be left unvacunmized or ungassed,the vacuumizing or gassing step in the chamber 41 is omitted. In suchcase the initial tucking-in of the wrapper 22 int-o the compound 28 onthe flange 27 is effected in such a manner as to tuck in the wrapperentirely around the package so .as to provide the continuous annularseal against the wrapper before trimming of the excess material of thewrapper and thereby omit the vents and the reseating step. This tuckingstep is immediately followed by the iiange bending step to produce theseam 23 as explained above.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the form, construction andarrangement of the parts and that changes may be made in the steps ofthe method described and their order of accomplishment without departingfrom the spirit and scope of the invention or sacrificing all of itsmaterial advantages, the form hereinbefore described being merely apreferred embodiment thereof.

We claim:

1. A frangibl'e shipping and display package, comprising a Wrapperformed of thin, exible, frangible and transparent plastic material, saidwrapper being adapted to hold and display a product and having amarginal edge portion extending laterally from said product, and a rigidsheet metal end member supporting said product and sealing the marginalportion of said wrapper, said end member having a surrounding skirt wallcarrying a sealing compound, said skirt wall merging into a curledperipheral ange including a convexly curved annular wall portionadjacent its peripheral edge and an adjacent inwardly projectingperipheral bead, said curved annular wall portion being held tightly bysaid bead against the marginal edge portion of said wrapper to clamp thesame tightly against the sealing compound on said skirt wall to providea tight end seam for permanently securing saidY wrapper to said endmember.

2. The package of claim 1 wherein the marginal edge portion of saidwrapper which is clamped against said sealing compound is doubled-backupon itself.

3. A frangible shipping and display package for comestibles, comprisinga rigid sheet metal base member for supporting the packaged product andterminating in a ,peripheral depending skirt wall, and a thin flexiblewrapper sheet formed of frangible transparent plastic material disposedover the comestible and covering the top and side walls thereof, saiddepending base member skirt wall merging into an outwardly and upwardlyextending ange terminating in an inwardly and downwardly extendingsmoothly curved wall disposed tangentially to said depending skirt walland cooperating with said outwardly and upwardly extending base memberflange as an open curl enclosing the marginal portion of said wrappersheet in a substantially hollow end seam joint, the terminal peripheralportion of said wrapper sheet extending beyond said curl and thencereversely upwardly into engagement with the exterior surface of saidsmoothly curved wall portion thereof and clamped thereby against thedownwardly extending wrapper sheet Iand against said skirt wall toconstitute a hermetically sealed union between said base member and saidsheet.

4. A frangible shipping and display package for comestibles, comprisinga rigid sheet metal base member for :supporting the packaged product andterminating in an annular depending skirt wall carrying a sealingcompound, and a thin flexible wrapper sheet formed of frangibletransparent plastic material disposed over the comestible and coveringthe top and side walls thereof and thence extending downwardly intoengagement with said sealing compound, said depending base member :skirtwall merging into an outwardly land upwardly extending iiangeterminating in an inwardly and downwardly extending smoothly curvedannular wall disposed tangentially to said depending skirt wall andcooperating with said outwardly and upwardly extending base memberflange as an open curl enclosing the marginal portion of said wrappersheet in a substantially hollow end seam joint, the terminal peripheralportion of said Wrapper sheet extending beyond said curl and thencereversely upwardly into engagement with the exterior surface of saidsmoothly curved wall thereof and cl'amped thereby against the downwardlyextending wrapper sheet portion embedded in said sealing compound andagainst said skirt wall to constitute a hermetically sealed unionbetween said base member and said wrapper sheet.

References Cited in the file of this patent UNITED STATES PATENTS1,613,282 Mayhew Jan. 4, 1927 1,689,018 Froidevaux Oct. 23, 19281,824,907 Lermer Sept. 29, 1931 1,848,834 Morse Mar. 8, 1932 2,012,529Eldredge Aug. 27, 1935 2,082,701 Kueffner June 1, 1937 2,200,200Donnelly May 7, 1940 2,343,550 Grove Mar. 7, 1944 2,468,517 SalsbergApr. 26, 1949 2,621,129 Ramsbottom Dec. 9, 1952 2,658,663 Reese Nov. 10,1953 2,690,593 Abercrombie Oct. 5, 1954 2,721,686 Reifsnyder et al. Oct.25, 1955

3. A FRANGIBLE SHIPPING AND DISPLAY PACKAGE FOR COMESTIBLES, COMPRISINGA RIGID SHEET METAL BASE MEMBER FOR SUPPORTING THE PACKAGED PRODUCT ANDTERMINATING IN A PERIPHERAL DEPENDING SKIRT WALL, AND A THIN FLEXIBLEWRAPPER SHEET FORMED OF FRANGIBLE TRANSPARENT PLASTIC MATERIAL DISPOSEDOVER THE COMESTIBLE AND COVERING THE TOP AND SIDE WALLS THEREOF, SAIDDEPENDING BASE MEMBER SKIRT WALL MERGING INTO AN OUTWARDLY AND UPWARDLYEXTENDING FLANGE TERMINATING IN AN INWARDLY AND DOWNWARDLY EXTENDINGSMOOTHLY CURVED WALL DISPOSED TANGENTIALLY TO SAID DEPENDING SKIRT WALLAND COOPERATING WITH SAID OUTWARDLY AND UPWARDLY EXTENDING BASE MEMBERFLANGE AS AN OPEN CURL ENCLOSING THE MARGINAL PORTION OF SAID WRAPPERSHEET IN A SUBSTANTIALLY HOLLOW END SEAM JOINT, THE TERMINAL PERIPHERALPORTION OF SAID WRAPPER SHEET EXTENDING BEYOND SAID CURL AND THENCEREVERSELY UPWARDLY INTO ENGAGEMENT WITH THE EXTERIOR SURFACE OF SAIDSMOOTHLY CURVED WALL PORTION THEREOF AND CLAMPED THEREBY AGAINST THEDOWNWARDLY EXTENDING WRAPPER SHEET AND AGAINST SAID SKIRT WALL TOCONSTITUTE A HERMETICALLY SEALED UNION BETWEEN SAID MEMBER AND SAIDSHEET.